Printable liquid crystal material

Abstract

The invention relates to the use of a printable polymerisable liquid crystal material as printable system for the preparation of polymers and pigments, to printable polymerisable liquid crystal materials and pigments and polymers prepared thereof, and to the use of the printable materials, pigments and polymers in optical, electrooptical, semiconductor and electronic applications and as birefringent and optically variable markings for decorative, security, authentification or identification applications.

The invention claimed is: 
     
       1. A method of preparing a polymer film or marking comprising printing a polymerizable liquid crystal material onto a substrate and polymerizing said liquid crystal material to form the polymer film or marking, wherein the polymerizable liquid crystal material does not contain a solvent, thinner, dispersion agent, polymeric binder, or a monomer compound that can be converted into the polymeric binder by polymerization, and wherein the polymerizable liquid crystal material comprises at least one compound of formula I and/or at least one compound of formula II 
       
         
           
           
               
               
           
         
         wherein 
         P is a polymerizable group, 
         Sp is a spacer group S—X, wherein S is alkylene with up to 20 C atoms which may be unsubstituted, mono- or poly-substituted in each case independently by F, Cl, Br, I or CN, one or more non-adjacent CH 2  groups to be optionally being replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         R is halogen, straight chain or branched alkyl with 1 to 20 C atoms, that is unsubstituted, mono- or polysubstituted, in each case independently, by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH 2  groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —OCO—O—, —SO 2 —, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         R 0  and R 00  are, independently of each other, H or alkyl with 1 to 12 C atoms, 
         L is F, Cl, Br, or an alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 12 C atoms, wherein one or more H atoms, each independently, are optionally replaced by F or Cl, and 
         r and s are independently of each other 0, 1, 2, 3 or 4. 
       
     
     
       2. A method according to  claim 1 , wherein the polymerizable LC material is polymerised at a temperature below 60° C. 
     
     
       3. A method of preparing a polymer film, marking or pigment, comprising printing said polymer film, marking or pigment with a polymerizable liquid crystal material comprising at least one compound of formula I and/or at least one compound of formula II 
       
         
           
           
               
               
           
         
         wherein 
         P is a polymerizable group, 
         Sp is a spacer group S—X, wherein S is alkylene with up to 20 C atoms which may be unsubstituted, mono- or poly-substituted in each case independently by F, Cl, Br, I or CN, one or more non-adjacent CH 2  groups to be optionally being replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         X is —O—, —S—, —CO—, —COO—, —OCO—, —CO—NR 0 —, —NR 0 —CO—, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —CX 1 ═CX 2 —, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond, 
         X 1  and X 2  are, independently of each other, H, F, Cl or CN, and 
         R is halogen, straight chain or branched alkyl with 1 to 20 C atoms, that is unsubstituted, mono- or polysubstituted, in each case independently, by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH 2  groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —OCO—O—, —SO 2 —, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         R 0  and R 00  are, independently of each other, H or alkyl with 1 to 12 C atoms, 
         L is F, Cl, Br, or an alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 12 C atoms, wherein one or more H atoms, each independently, are optionally replaced by F or Cl, and 
         r and s are independently of each other 0, 1, 2, 3 or 4, and the polymerizable liquid crystal material does not contain a solvent, thinner, dispersion agent, polymeric binder, or a monomer compound that can be converted into the polymeric binder by polymerization. 
       
     
     
       4. A method according to  claim 3 , wherein the polymerizable liquid crystal material is a nematic material. 
     
     
       5. A method according to  claim 3 , wherein the polymerizable liquid crystal material is a chiral nematic or cholesteric material. 
     
     
       6. A method according to  claim 3 , wherein the polymerizable liquid crystal material has either a nematic phase or a chiral nematic or cholesteric phase at room temperature. 
     
     
       7. A method according to  claim 3 , wherein the polymerizable liquid crystal material comprises at least one chiral compound which can be polymerizable or non-polymerizable. 
     
     
       8. A method according to  claim 3 , wherein the polymerizable liquid crystal material comprises at least one compound of formula I and/or II wherein R is a chiral group. 
     
     
       9. A method according to  claim 3 , wherein the polymerizable liquid crystal material comprises at least one compound which induces and/or enhances planar alignment. 
     
     
       10. A method according to  claim 3 , wherein the polymerizable liquid crystal material further comprises at least one polymerizable mesogenic compound having two or more polymerizable groups. 
     
     
       11. A method according to  claim 3 , wherein the polymerizable liquid crystal material further comprises at least at least one polymerizable mesogenic compound having one polymerizable group. 
     
     
       12. A method according to  claim 3 , wherein the polymerizable liquid crystal material comprises
 3-60% of one or more direactive mesogenic compounds, 
 7-90% of one or more monoreactive mesogenic compounds of formula I and II, 
 0 to 70% of one or more further monoreactive mesogenic compounds, 
 0.1 to 10% of one or more surfactants, and 
 0.1 to 10% of one or more photoinitiators. 
 
     
     
       13. A polymerizable liquid crystal material comprising at least one compound of formula I and at least one compound of formula II 
       
         
           
           
               
               
           
         
         wherein 
         P is a polymerizable group, 
         Sp is a spacer group S—X, wherein S is alkylene with up to 20 C atoms which may be unsubstituted, mono- or poly-substituted in each case independently by F, Cl, Br, I or CN, one or more non-adjacent CH 2  groups to be optionally being replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         X is —O—, —S—, —CO—, —COO—, —OCO—, —CO—NR 0 —, —NR 0 —CO—, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —CX 1 ═CX 2 —, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond, 
         X 1  and X 2  are, independently of each other, H, F, Cl or CN, and 
         R is halogen, straight chain or branched alkyl with 1 to 20 C atoms, that is unsubstituted, mono- or polysubstituted, in each case independently, by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH 2  groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —OCO—O—, —SO 2 —, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, 
         R 0  and R 00  are, independently of each other, H or alkyl with 1 to 12 C atoms, 
         L is F, Cl, Br, or an alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 12 C atoms, wherein one or more H atoms, each independently, are optionally replaced by F or Cl, and 
         r and s are independently of each other 0, 1, 2, 3 or 4, and the polymerizable liquid crystal material does not contain a solvent, thinner, dispersion agent, polymeric binder, or a monomer compound that can be converted into the polymeric binder by polymerization. 
       
     
     
       14. A liquid crystal polymer, liquid crystal pigment, oriented liquid crystal polymer film or marking obtained from a polymerizable liquid crystal material according to  claim 13 . 
     
     
       15. A liquid crystal pigment obtained from a polymer or polymer film produced from a polymerizable liquid crystal material according to  claim 13 . 
     
     
       16. An optical, electrooptical, decorative, security, cosmetic, diagnostic, electric, electronic, charge transport, semiconductor, optical recording, electroluminescent, photoconductor or electrophotographic item comprising a polymerisable liquid crystal material according to  claim 13 , or a liquid crystal polymer, liquid crystal pigment, oriented liquid crystal polymer film or marking obtained from said polymerisable liquid crystal material. 
     
     
       17. A decorative, security, authentication or identification marking, thread or device comprising a polymerizable liquid crystal material according to  claim 13 , or a liquid crystal polymer, liquid crystal pigment, oriented liquid crystal polymer film or marking obtained from said polymerizable liquid crystal material. 
     
     
       18. A decorative, security, authentication or identification marking, thread or device according to  claim 17 , comprising at least two chiral nematic materials that differ from each other in their handedness and/or their reflection color and/or their color flop. 
     
     
       19. An object, document of value or hot stamping foil comprising a decorative, security, authentication or identification marking, thread or device according to  claim 18 . 
     
     
       20. A polymerizable liquid crystal compound that is of formula IIa 
       
         
           
           
               
               
           
         
       
     
     
       21. A polymerizable liquid crystal material comprising the compound of  claim 20  and the compound of formula Ia 
       
         
           
           
               
               
           
         
       
     
     
       22. A polymerizable liquid crystal material according to  claim 13 , wherein
 in the compound of formula I or II, 
 r and s are 0, 
 P is an acrylate, methacrylate, vinyl or epoxy group, 
 L is F or methyl, or 
 R is straight chain alkyl with 1 to 15 C atoms, or 
 wherein in the compound of formula I, 
 r is 1 or 2, or 
 wherein in the compound of formula II, 
 r or s is 1 or 2, or both r and s are 1 or 2. 
 
     
     
       23. A polymerizable liquid crystal material according to  claim 13 , wherein in the compound of formula I and/or II, R is a chiral group. 
     
     
       24. A method according to  claim 1 , wherein the polymerizable liquid crystal material has a nematic or cholesteric phase at 10° C. 
     
     
       25. A method according to  claim 3 , wherein the polymerizable liquid crystal material has a nematic or cholesteric phase at 10° C. 
     
     
       26. A material according to  claim 13 , wherein the polymerizable liquid crystal material has a nematic or cholesteric phase at 10° C.